Assessing The Utility of D-Dimer Driven Anticoagulation Strategies In Severely Obese Patients With COVID-19

Funding Acknowledgements

Type of funding sources: None.

Background

Many studies to date have documented significant inflammatory vascular sequelae in association with COVID-19. Current guidelines suggest an initial strategy of therapeutic-dose anticoagulation to non-critically ill, hospitalized patients requiring low-flow oxygen and a concurrent D-dimer level above the upper limit of normal. However, the utility of D-dimer values in predicting thrombosis in severely obese patients are equivocal to poor, with prior evidence suggesting falsely elevated levels with greater BMI. Given the weight-based dosing of heparin, these patients may also be inadvertently at elevated risk for major bleeds.

Purpose

To examine the utility of D-dimer levels in risk stratification and anticoagulation therapy in non-critically ill COVID-19 patients with severe obesity.

Methods

In this single-center, retrospective study, 32 severely obese patients (defined as BMI > 40) hospitalized with COVID-19 and requiring low flow oxygen delivery, without ICU level of care were analyzed. Clinical outcomes were compared between groups receiving therapeutic versus prophylactic doses of anticoagulation. All were treated with low molecular weight heparin (LMWH) per hospital protocol. The following data points were examined: length of hospitalization, mortality, anticoagulation therapy, initial d-dimer levels, thrombotic events, minor/major bleeds, and oxygen modality.

Results

In total, 78% of patients initially presented with a D-dimer level above the upper limit of normal, with 53% of patients meeting criteria for therapeutic anticoagulation. However, there were no significant differences in incidence of thrombotic events, mean length of hospitalization or overall mortality. Furthermore, despite utilization of appropriate therapeutic anticoagulation, it did not reduce the overall use of oxygen support requirements, including high flow oxygen or non-invasive ventilation, when compared to individuals receiving prophylactic dosing.

Conclusion

The clinical utility of D-dimer levels for guiding anticoagulation therapy in severely obese patients with COVID-19 may be limited. Here, we demonstrate that therapeutic dose approaches have nonsignificant differences in clinical outcomes when compared to prophylactic doses in this distinct population.

Differential diagnosis of myelofibrosis based on WHO 2008 criteria: acute panmyelosis with myelofibrosis, acute megakaryoblastic leukemia with myelofibrosis, primary myelofibrosis and myelodysplastic syndrome with myelofibrosis

INTRODUCTION

The aim of this study was to characterize clinicopathological features of acute panmyelosis with myelofibrosis (APMF), acute megakaryoblastic leukemia with myelofibrosis (AMKL-MF), primary myelofibrosis (PMF) and myelodysplastic syndrome with myelofibrosis (MDS-MF) in order to provide the keys to the differential diagnosis of bone marrow (BM) fibrosis.

METHODS

We compared age, gender, splenomegaly, serum lactate dehydrogenase level, blood cell counts, blast counts in peripheral blood (PB) and BM, megakaryocyte counts, BM cellularity, dysplasia, and the karyotypes of patients with APMF (n = 6), AMKL-MF (n = 7), PMF (n = 44), and MDS-MF (n = 44).

RESULTS

APMF showed hyperplasia of all three lineages, increase in megakaryocyte count with dysplasia and frequent abnormal karyotypes. AMKL-MF was associated with elevated BM blast counts, decreased BM megakaryocyte count with rare megakaryocytic dysplasia and chromosome 21 abnormality. PMF patients displayed splenomegaly, rare blasts in PB/BM, and JAK2 V617F mutation. MDS-MF patients showed pancytopenia, dysplasia in all three lineages and recurrent chromosomal abnormalities involving chromosome 5,7,12, and 17.

CONCLUSIONS

Although differential diagnosis among APMF, AMKL-MF, PMF, and MDS-MF is very challenging due to the overlapping clinical and morphological features, meticulous investigation of the patient with respect to splenomegaly, blood cell count, PB and BM findings, and karyotype will serve as a guide to correct diagnosis.

Glucocorticoid-induced tumour necrosis factor receptor-related protein-mediated macrophage stimulation may induce cellular adhesion and cytokine expression in rheumatoid arthritis

Glucocorticoid-induced tumour necrosis factor receptor (TNFR)-related protein (GITR) is one of the T cell co-stimulatory molecules and is associated with the pathogenesis of a number of autoimmune diseases. We investigated the expression patterns of GITR in human arthritic synovium and the role of GITR in the pathogenesis of rheumatoid arthritis (RA). Immunohistochemical analyses revealed the expression of GITR and its cognate ligand, GITRL, in macrophages in RA, but not in osteoarthritis (OA), synovium. To investigate the role of GITR in macrophage functions, primary macrophages from RA patients and a human macrophage cell line, THP-1, were analysed. Stimulation of the macrophages with anti-GITR monoclonal antibody induced up-regulation of intercellular adhesion molecule (ICAM)-1 and subsequent aggregation/adhesion, which was enhanced by the presence of extracellular matrix proteins and blocked by anti-ICAM-1 monoclonal antibody. The validity of these in vitro observations was confirmed by immunohistochemical analyses of RA synovium, which showed strong expression of ICAM-1 in GITR-positive macrophages. Additionally, GITR stimulation induced expression of proinflammatory cytokines/chemokines and matrix metalloproteinase-9 in synovial macrophages. These data indicate that GITR, expressed on macrophages in human RA synovium, may enhance inflammatory activation of macrophages by promoting cytokine gene expression and adhesion between cells and to extracellular matrix in RA synovium.

The effects of curcumin on the invasiveness of prostate cancer in vitro and in vivo

Curcumin has become a focus of interest with regard to its antitumor effects in prostate cancer; however, the effects of this agent on invasion and metastasis remain less well understood. Matrix metalloproteinases (MMPs) are important prerequisite for tumor invasion and metastasis. In this study, we evaluated the effects of curcumin on prostate cancer cells (DU-145) invasion in both in vitro and in vivo. We utilized zymography and ELISA in order to determine the MMP-2 and MMP-9 activity. Matrigel invasion assay was performed to assess cellular invasion. We developed a xenograft model to examine tumorigenicity. Curcumin treatment resulted not only in a significant reduction in the expression of MMP-2 and MMP-9, but also effected the inhibition of invasive ability in vitro. Curcumin was shown to induce a marked reduction of tumor volume, MMP-2, and MMP-9 activity in the tumor-bearing site. The metastatic nodules in vivo were significantly fewer in the curcumin-treated group than untreated group. Curcumin appears to constitute a potential agent for the prevention of cancer progression, or at least of the initial phase of metastasis, in prostate cancer.

Preparation and Characterization of Ceramic Hollow Microspheres for Heavy Metal Ion Removal in Wastewater

Ceramic hollow microspheres (CHMSs) were prepared to use as supports for the removal of heavy metal ions from industrial waste-water. A water extraction sol-gel technique was used to prepare porous CHMS by extracting water from an emulsion of LUDOX (silica colloid; SiO(2), Aldrich Co.) and 2-ethyl-1-hexanol. Experiments were conducted to control pore size, wall thickness, and separation yield by examining the ratio of precursors (LUDOX and 2-ethyl-1-hexanol), catalyst (NH(4)OH), sintering temperature, surfactant (SPAN 80), extractant (n-butanol), stirring speed, and concentration of precursor (LUDOX). The results revealed that the optimum conditions were 20 ml of a 10 wt% solution of LUDOX, 10 ml of NH(4)OH, a sintering temperature of 500 degrees C, 0.4 ml of SPAN 80, 200 ml of n-butanol, and a stirring speed of 730 rpm/100 ml of 2-ethyl-1-hexanol. CHMSs were impregnated in Cyanex 272 and examined for their ability to remove heavy metal ions from a solution. Based on an experiment involving the removal of metal ions using CHMSs that were prepared under optimum conditions, Zn ion was removed at a level of 0.354 mmol/g at pH 4, which was about twice the adsorption capacity of CHMSs prepared by Wilcox (Mater. Res. Soc. Symp. Proc. 346, 201 (1994)). Copyright 2000 Academic Press.

Fringe forms a complex with Notch

The Fringe protein of Drosophila and its vertebrate homologues function in boundary determination during pattern formation. Fringe has been proposed to inhibit Serrate-Notch signalling but to potentiate Delta-Notch signalling. Here we show that Fringe and Notch form a complex through both the Lin-Notch repeats and the epidermal growth factor repeats 22-36 (EGF22-36) of Notch when they are co-expressed. The Abruptex59b (Ax59b) and AxM1 mutations, which are caused by missense mutations in EGF repeats 24 and 25, respectively, abolish the Fringe-Notch interaction through EGF22-36, whereas the l(1)N(B) mutation in the third Lin-Notch repeat of Notch abolishes the interaction through Lin-Notch repeats. Ax mutations also greatly affect the Notch response to ectopic Fringe in vivo. Results from in vitro protein mixing experiments and subcellular colocalization experiments indicate that the Fringe-Notch complex may form before their secretion. These findings explain how Fringe acts cell-autonomously to modulate the ligand preference of Notch and why the Fringe-Notch relationship is conserved between phyla and in the development of very diverse structures.

The inturned protein of Drosophila melanogaster is a cytoplasmic protein located at the cell periphery in wing cells

The inturned (in) gene is a component of the frizzled (fz) signaling pathway that controls the polarity of hairs and bristles in the epidermis of Drosophila. It appears to act downstream of fz, which encodes a putative receptor for a tissue polarity signal. The in gene encodes a novel protein that had been suggested to contain two potential transmembrane domains. It has been suggested that the In protein interacts with the actin cytoskeleton to regulate the formation of the pupal wing prehairs that become adult hairs. The initiation of prehairs is normally restricted to the vicinity of the distal most vertex along the apical surface of the pupal wing cells. In an in mutant, prehairs initate at a variety of locations along the apical cell periphery. We have used immunofluorescence to study the subcellular localization of the In protein. When expressed in cultured cells, we found that In is a cytoplasmic protein. However, we found that it is localized in the vicinity of plasma membrane and the cortical actin cytoskeleton of Drosophila wing disc and pupal wing cells. Thus, in wing cells the In protein is localized to the region of the cell where it appears to function. This subcellular localization presumably requires the function of other proteins and may represent a regulatory mechanism. Our data suggest that fz does not play a major role in the subcellular localization of In. The In protein is notably insoluble in buffers containing high salt and nonionic detergents. This lack of solubility is significantly reduced in fz and mwh mutants, implying that it may be related to the mechanism of in function.

Developmental analysis of the ovarian tumor gene during Drosophila oogenesis

Severe alleles of the ovarian tumor (otu) and ovo genes result in female sterility in Drosophila melanogaster, producing adult ovaries that completely lack egg chambers. We examined the developmental stage in which the agametic phenotype first becomes apparent. Germ cell development in embryos was studied using a strategy that allowed simultaneous labeling of pole cells with the determination of embryonic genotype. We found that ovo- or otu- XX embryonic germ cells were indistinguishable in number and morphology from those present in wild-type siblings. The effects of the mutations were not consistently manifested in the female germline until pupariation, and there was no evidence that either gene was required for germ cell viability at earlier stages of development. The requirement for otu function in the pupal and adult ovary is supported by temperature-shift experiments using a heat-inducible otu gene construct. We demonstrate that otu activity limited to prepupal stages was not sufficient to support oogenesis, while induction during the pupal and adult periods caused suppression of the otu mutant phenotype.

The somatic sex determines the requirement for ovarian tumor gene activity in the proliferation of the Drosophila germline

Gametogenesis in Drosophila requires sex-specific interactions between the soma and germline to control germ cell viability, proliferation, and differentiation. To determine what genetic components are involved in this interaction, we examined whether changes in the sexual identity of the soma affected the function of the ovarian tumor (otu) and ovo genes. These genes are required cell autonomously in the female germline for germ cell proliferation and differentiation. Mutations in otu and ovo cause a range of ovarian defects, including agametic ovaries and tumorous egg cysts, but do not affect spermatogenesis. We demonstrate that XY germ cells do not require otu when developing in testes, but become dependent on otu function for proliferation when placed in an ovary. This soma-induced requirement can be satisfied by the induced expression of the 98 × 10(3) M(r) OTU product, one of two isoforms produced by differential RNA splicing. These results indicate that the female somatic gonad can induce XY germ cells to become ‘female-like’ because they require an oogenesis-specific gene. In contrast, the requirement for ovo is dependent on a cell autonomous signal derived from the X:A ratio. We propose that differential regulation of the otu and ovo genes provides a mechanism for the female germline to incorporate both somatic and cell autonomous inputs required for oogenesis.

Molecular characterization of ovarian tumors in Drosophila

Certain female-sterile mutations in Drosophila result in the uncontrolled proliferation of X/X germ cells. It has been proposed that this ovarian tumor phenotype results from the sexual transformation of X/X germ cells to a male identity. We present findings inconsistent with this model. We demonstrate that the tumorous cells produced by mutations in the ovarian tumor (otu), Sex-lethal (Sxl) and sans fille (snf) genes are capable of female-specific transcription and RNA processing. This indicates that these ovarian tumor cells still retain some female identity. Therefore, we propose that mutations in these genes do not cause a male transformation of the X/X germ line but instead either cause an ambiguous sexual identity or block specific stages of oogenesis. Our findings indicate that while Sxl is the master sex determination gene in somatic cells, it appears to play a more subsidiary role in the germ line. Finally, we demonstrate that the germ line function of Sxl depends on the activity of a specific OTU isoform.

Changes in coronary haemodynamics and myocardial metabolism at rest and during exercise after a cardiotonic drug (prenalterol) in patients with coronary artery disease

To elucidate the myocardial metabolic and haemodynamic effects of an inotropic drug in patients with coronary artery disease (CAD) without evident congestive heart failure (CHF), the acute effects of prenalterol were studied in nine patients. Patients with documented CAD by leftsided cardioangiography and end-diastolic pressure greater than 15 mm Hg were included in the study. They were examined at rest and during supine exercise at a level just below their anginal threshold before and after prenalterol. At rest, rate pressure product (RPP) increased by 40% (P less than 0.01), cardiac index rose 20% (P less than 0.01), cardiac venous flow (CVF) increased by 18% (P less than 0.05), and myocardial oxygen consumption (MVO2) increased by 20% (P less than 0.05) after prenalterol administration. Despite a decrease in mean pulmonary capillary venous pressure (PCV) of 40% (P less than 0.01), myocardial lactate extraction fell significantly (P less than 0.01) and lactate production was observed in three of nine patients compared to before prenalterol administration. During exercise, RPP increased by 20% (P less than 0.01), cardiac index remained unchanged, CVF increased by 25% (NS) and MVO2 showed a tendency to an increase (NS) after prenalterol administration. Mean PCV pressure decreased by 30% (P less than 0.01). Myocardial lactate extraction was markedly reduced during exercise (P less than 0.01) and five of nine patients showed lactate production compared to that before prenalterol administration. Thus, despite a decrease in left ventricular filling pressure, increased myocardial oxygen demand occurred after acute administration of prenalterol. Prenalterol and probably similar inotropic drugs should be used cautiously in patients with CAD without clinical evidence of congestive heart failure.

Identification of patients at risk of symptomatic cytomegalovirus infection after open-heart surgery

In a prospective study, 58 consecutive patients submitted to open-heart surgery were followed from the preoperative period up to 3 months postoperatively with regard to clinical status, cytomegalovirus (CMV) antibodies and signs of enzymatic liver damage. Forty-eight patients (83%) were seropositive prior to operation. Of the ten (17%) preoperatively seronegative patients, five became CMV-seropositive during follow-up. Of the 48 initially seropositive patients, nine showed heightened CMV-antibody titers after the operation. Significant symptomatic CMV illness with protracted fever developed in four patients, all from the group of five with seroconversion. All five of these patients had enzymatic liver damage. The incidence of symptomatic CMV infection after open-heart surgery in CMV-negative patients probably is higher than previously assumed, while CMV-positive patients seem to have complete protection against CMV morbidity.

Phase II study of 4'-epi-doxorubicin in metastatic renal cancer

In 20 patients with measurable metastatic renal cancer 4'-epi-doxorubicin (Adriamycin) administration (75 mg/m2, every 3 weeks) did not result in any tumor remission. Hematologic and gastrointestinal toxicity was generally mild to moderate. Anthracycline-induced cardiac side effects were not observed in any of the patients.